Extend niceness check to handle tabs as well
Extend niceness check to handle tabs as well

Report tabs also as niceness errors

Change-Id: I5aa2e25af5c21005a67c9b7b2bfac57ffc87a624

savinash47/openstack-doc-tools,savinash47/openstack-doc-tools,openstack/openstack-doc-tools,savinash47/openstack-doc-tools,openstack/openstack-doc-tools